In response to demand for energy-saving in electrophotographic image forming apparatuses, to reduce energy consumed in the fixing device, whose consumption of electric power is the highest in the image forming apparatus, low-temperature fixing to perform image fixing at a relatively low temperature is promoted.
In order to accomplish low-temperature fixing, it is necessary to melt a binder resin contained in toner, and a mold releasing agent (hereinafter, also denoted as a releasing agent) at a relatively low fixing temperature, and it is contemplated to use a binder resin contained in toner, and a releasing agent (wax) which exhibit a low melt viscosity.
Further, in order to obtain a toner in response to such a low fixing temperature, it is necessary to use a releasing agent exhibiting a relatively low melting point and toners obtained by use of releasing agents exhibiting a low melting point (hereinafter, also referred to as a low-melting point releasing agent) were disclosed (refer to Patent Documents 1 and 2).
From a viewpoint of environmental conservation, further reduction of energy consumed by an image forming apparatus is desired, and improvement in fixing efficiency with a fixing device, together with development of toner used for the foregoing low temperature fixing has also been investigated. As such a fixing device, disclosed is a fixing device equipped with a heating roller and a belt-shaped pressure body in combination in place of one equipped with a heating roller and a pressure roller in combination (refer to Patent Document 3, for example).
This fixing device is one by which fixing efficiency is improved by employing a belt-shaped member for a pressure body to expand the nip portion width in the fixing area.
(Patent Document 1) Japanese Patent O.P.I. Publication No. 2000-321815
(Patent Document 2) Japanese Patent O.P.I. Publication No. 2000-275908
(Patent Document 3) Japanese Patent O.P.I. Publication No. 10-228198